informer

1. 1

   One who informs someone else about something.

2. 2

   A person who tells authorities about improper or illegal activity.

   • Being an informer often meant living in fear.
   • The police relied on an informer to catch the gang.
3. 3

   One who informs, animates, or inspires.

   • 1729, Alexander Pope, Prologue to Sophonisba (by James Thomson Nature, informer of the poet's art.

syn. informant